fishless cycling

["Adam N." <adam at xhaos_org>]

Tom Barr wrote:

I added mulm from another tank and had my tank cycle in 0.0 weeks. How is
fishless cycling going to beat that? That works on non planted tanks also.
No hassle, no testing needed, no wait, no problem.

I would have to say that this is not true, at least not how I think it is
meant.  The tank would cycle from Ammonia to Nitrite, and then more seed
culture would have to be added for the nitrite to nitrate phase.  I don't
think much of the nitrite to nitrate bacteria would survive because
initially there would be no food for them.  At any rate it wouldn't support
much of a biological load unless you added a lot of substrate or mulm from
the seed tank. This method can substantially shorten the cycle but not
eliminate it.  It could eliminate it if you only want to add a tiny fish
load.  The whole tank has to get colonized, and that takes some time and a
food source.  The only way to get that without fish is to add a food source
over time.  I still don't see the advantage or understand why one would want
to drop in a ton of fish at once, unless one were moving or something like
that.

Personally, I run filterless tanks so this is totally academic to me.
However, I do fishlessly cycle planted tanks.  The plants go in about two
weeks before the fish and I start feeding them immediately. Fish only go in
when the initial die back and wobble are over, basically when the plants
begin to 'take' do fish go in.  Fish and plants together is just to many
variables in the new environment for me.

I believe fishless cycling may be reasonable in marine tanks where the fish
are very sensitive/delicate/expensive.

Adam